<html>
<head>
<link rel="stylesheet"href="bootstrap-3.3.2-dist/css/bootstrap.css"/>
<link rel="stylesheet"href="bootstrap-3.3.2-dist/css/bootstrap-theme.css"/>
<script type="text/javascript"src="bootstrap-3.3.2-dist/js/bootstrap.js"></script>
<link rel="stylesheet"href="//maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css"/>

</head>
<style>
.classTittle{
background-color: burlywood;
width: 498px;
height: 20px;
font-size: 32;
color: darkred;
}
.class01{
font-size:25px;
}
.class02{
height: 33px;
width: 63px;
font-size:27px;
color: red;
}
.class03{
height: 37px;
width: 280px;
color: red;
font-size: 20px;

}
.class04{
background-color: cyan;
font-size: 32;
width: 87px;
color: white;
height: 39px;
}
</style>
<meta http-equiv="content-Type" content="text/html;charset=utf-8"/>
<body>
<?php
if(isset($_POST["a"]) && isset($_POST["b"]))
{
	$a=$_POST["a"];
	$b=$_POST["b"];
	if($a == 0)
	{
		if($b != 0)
		{
			$x = "Phương trình vô nghiệm";
		}
		else
			$x = "Phương trình vô số nghiệm";
	}
	else
		$x = ("x = ").(-$b / $a);
}
?>
<form align="center"action="giaiphuongtrinhbacnhat.php" method="post" name="form1" id="form1">
<table  align="center" cellspacing="0">
<tr style="background-color: bisque;">

<div class="div_vd_font_awesome">
<ul class="fa-ul">
  <li><i class="fa-li fa fa-check-square"></i>List icons</li>
  <li><i class="fa-li fa fa-check-square"></i>can be used</li>
  <li><i class="fa-li fa fa-spinner fa-spin"></i>as bullets</li>
  <li><i class="fa-li fa fa-square"></i>in lists</li>
</ul>

<i class="fa fa-spinner fa-spin"></i>
<i class="fa fa-circle-o-notch fa-spin"></i>
<i class="fa fa-refresh fa-spin"></i>
<i class="fa fa-cog fa-spin"></i>
<i class="fa fa-spinner fa-pulse"></i>
</div>
<form class="form-inline"align="center">
<div>
<h3>GIẢI PHƯƠNG TRÌNH BẬC NHẤT</h3>
</div>

</form>
<td colspan="3" align="center" class="classTittle"><span>GIẢI PHƯƠNG TRÌNH BẬC NHẤT</span></td>
</tr>
<tr style="background-color: bisque;">
<td class="class01"><span>phương trình:</span></td>
<td align="center"><label><input class="class02"name="a"id="a"type="text"value="
<?php 
if(isset($_POST["a"]))
{
	echo $_POST["a"]; 
}

?>"/></label ><span class="class01">      x + </span></td>
<td><label><input class="class02"name="b"id="b"type="text"value="<?php if(isset($_POST["b"])){echo $_POST["b"];}?>"/></label><span class="class01">  = 0</span></td>
</tr>
<tr style="background-color: bisque;">
<td class="class01"><span>Nghiệm:</span></td>
<td colspan="2"><label><input  style="background-color:gold;"readonly="true"class="class03"name="x"id="x"value="<?php if(isset($_POST["x"])){echo $x;}?>"/></label></td>
</tr>
<tr style="background-color: bisque;">
<td colspan="3" align ="center"><label><input class="btn btn-primary"name="submit" type="submit" value="Tính"/></label></td>
</tr>
</table>
</form>
</body>
</html>